A hand strapped or carried GNSS device 101 used by a walking user 103, e.g. as shown in FIG. 1 presents a challenge to a GNSS Measurement engine (ME) because the antenna movements 102 cause a pattern of cyclic loss of power with periodic intervals of increased and reduced SNR levels. This is mainly due to the inherent directionality of the antenna and the fact that while the user is walking or running, his hand periodically changes the angle relative to the sky. This signal behaviour can cause up to 10 dB Hz jumps in the received signal 106, 107, and results in degraded search and tracking of satellite vehicles (SVs) 104, 105 over time. Typically the ME drops SVs because of sudden power drops or in general performs worse due to the short intervals of low SNRs. The problem is aggravated in tough urban conditions, where the signal can have a significant SNR degradation in the first place, and bad antenna angles (even if instantaneous) can bring it to be absolutely invisible. GNSS SVs searching and tracking especially in low power level signals (<20 dB Hz) will have vast performance degradations as the mechanisms work in continuous periods which can last for several seconds (non-coherent integrations) and SNR drops in within these periods will result in very poor GNSS receiver performance and user experience.
There is a need to find a solution for improving the detection performance of a GNSS device in the above described scenarios of antenna movements, in particular caused by a pedestrian user carrying the GNSS device.